1. Field of the Invention
Exemplary embodiments of the present invention relate to a scaffold for tissue regeneration, and more particularly to a three-dimensional nanofibrous scaffold for tissue regeneration, in which can be increased in thickness and porosity in a simple manner by ultrasonication, and a method for fabricating the same.
2. Background of the Related Art
The human body is very limited in tissue's ability to self-regenerate because the tissue has a significantly complex and delicate structure. The human body possesses a possibility of tissues being regenerated when tissues are damaged owing to stem cells, but there may occur the case that goes beyond a limitation of a tissue regeneration function due to the reason of incident, illness, aging, or the like. Recently, the need for regeneration of organs or tissues of the body is sharply increasing since they encounter a limitation of the ability to regenerate due to an increase in a variety of diseases and incidents along with the rapid entry into an aging society.
In addition, the demand for development of a technology capable of effectively replacing or implanting biological tissues is increasing gradually, and an effort to restore organs and tissues of the human body has been greatly spotlighted for a long time. Initially, an effort were attempted for the development of biocompatible materials for an artificial substitute, organ transplantation, and the like, but such a technology is recently advanced to the tissue engineering that incorporates and applies biological science, engineering, and medical science.
The tissue engineering is a field of regenerative medicine which deals with regeneration of body tissues from cells to artificial organs, and is recognized as one of important technologies of a biological science and a medical field in future based on the science that deals with biological and engineering technologies involving biomaterials that can help to restore tissues or organs. A research is in progress on various methods for achieving a goal to restore, maintain, and improve the function of the human body by understanding the correlation between the structure and function of biological tissues, and furthermore fabricating and implanting biological substitutes.
In the tissue engineering, to produce a scaffold that functions as a support to allow cells to adhere and grow is one of core technologies. Unlike a two-dimensional membrane or capsule, the scaffold is formed in a three-dimensional shape and refers to a space where all the cells having a three-dimensional structure in vivo can adhere, proliferate, and differentiate.
The scaffold plays a very important role in the tissue engineering. In addition, the scaffold plays a significant role in growth of cells disseminated in a porous structure and cells migrated from tissue surroundings. Almost all the cells in vivo are adherent cells that adhere and grow. If there is no a place for the cells to adhere, they do not grow but perish. Thus, it is required that the scaffold should provide an environment suitable for adhesion, growth, and differentiation of cells as well as cell migration. The scaffold can be prepared of various materials, and a research is actively being conducted to develop a scaffold for tissue regeneration using a natural material, a synthetic polymer, a biological ceramics, and a polymer-ceramic composite material.
The scaffold has a structure that needs a high porosity to secure a large surface area enabling cell adhesion at a high density, and requires an open cellular structure in which large pores enabling formation of a blood vessel, and delivery of a substance such as nutrient, growth factor, hormone, or the like, after implantation in vivo are connected to each other. In addition, it is required that porosity and the shape of pores of the scaffold should be controlled depending on the properties of tissues cultured.
As examples of a technique for preparing a sponge type porous scaffold, particulate leaching, emulsion freeze-drying, high-pressure gas expansion, phase separation, and the like have been generally accepted. However, such a conventional scaffold preparation method has a limitation in the production of pores having an open cellular structure, and entails a problem in that the pore size is too small to culture cells three-dimensionally.